We operate two TM powered 135 50% in the hover and both need their tails painting on a regular basis. Using the thermal camera you can see the abuse the tail gets in the hover. Air Glaze is being trialled next to see if that improves the longevity of the tail paint. The affected area is just after the exhausts up to the stabilizer.
But thats a different cause, the heat. I saw the newer Ts have extra "heatshields" right behind the exhaust pipes.